Method for Powering and Terminating Operation of Vehicle Accessories with Engine Off

ABSTRACT

The intent of this invention is to minimize the possibility of exhausting the vehicle battery while still permitting operation of specific accessories with the engine off. The invention proposes to accomplish this by powering and terminating the operation of an accessory through and under the control of any type of no idle HVAC system or as a free standing auxiliary, accessory powering system having its own means of termination.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Application Ser. No.61/174,057, filed Apr. 30, 2009, the disclosure of which is incorporatedherein by reference.

BACKGROUND

The present invention relates to powering vehicle accessories orauxiliary systems when the vehicle's engine is off. More specifically,it relates to powering and terminating operation of such accessoriessimultaneously with the powering and terminating operation of no engineidle interior heating or cooling systems, whether of the fuel fired orenergy recovery type for cold weather use, or no idle air conditioningor ventilating systems operating from auxiliary batteries.

Operating commercial vehicle fleets frequently requires the presence ofthe operator within the vehicle cab for rest, meal and paper work stopsor while the vehicle is waiting to load or unload. With the driverpresent, it becomes desirable to provide the means for operatingaccessories such as AM/FM radios, communication radios, lighting, orother accessories that normally function when the ignition is on and theengine is running but not when the ignition is off.

The intent of this invention is to minimize the possibility ofexhausting the vehicle battery while still permitting operation ofspecific accessories with the engine off. The invention proposes toaccomplish this by powering and terminating the operation of anaccessory through and under the control of any type of no idle HVACsystem or as a free standing auxiliary, accessory powering system havingits own means of termination.

Although accessories can be wired to operate with the engine off, theprocess introduces the significant danger or inconvenience of theaccessory being left indefinitely on by accident, exhausting the limitedpower available from a vehicle's storage battery, and putting at riskthe ability to restart the vehicle's engine. Some accessories may beoperated in some make or model vehicles by turning the ignition key tothe accessory position. However, as with many types of no idle HVACsystems, turning the key to the ignition or accessory on position isinterpreted as ignition on, thus interfering with proper operation ofthe HVAC system.

Other aspects, objects and advantages of the present invention,including the various features used in various combinations, will beunderstood from the following description according to illustrativeembodiments of the present invention, taken in conjunction with thedrawings in which certain specific features are shown.

SUMMARY

The intent of this invention is to minimize the possibility ofexhausting the vehicle battery while still permitting operation ofspecific accessories with the engine off. The invention proposes toaccomplish this by powering and terminating the operation of anaccessory through and under the control of any type of no idle HVACsystem or as a free standing auxiliary, accessory powering system havingits own means of termination.

The termination means for either would be based on specific occurrencessuch as opening of a cab door or a combination of prioritized andsequenced criteria, like low battery voltage, timed operation or anyother appropriate terminating signal obtained from the vehicle,integrated into the HVAC system, or programmable by the installer oreven the user at time of initiation.

With either the independent or HVAC integrated versions, operation is asfollows. During engine operation, the accessory is powered through theignition system and may be turned on or off by the driver using theaccessory's on/off switch. When the engine [ignition] is off and theauxiliary HVAC system is turned on, the accessory is powered in parallelthrough and under the control of the no idle HVAC system and theaccessory may once again be turned on or off by the vehicle operator.

When an auxiliary HVAC system, of the energy recovery type, for example,terminates operation because engine coolant temperature has droppedbelow a certain temperature or because of low battery voltage, theaccessory ceases operation as well.

In the case of the independent version of this invention, which is notpart of an HVAC system containing a terminating system, the independentsystem would be equipped with its own terminating devices that may ormay not be based on criteria similar to those used in the auxiliary HVACsystem.

In the case of fuel fired no idle heating systems however, operation ofthe system may extend beyond the limited capacity of the electricalsystem to maintain operation of the accessory. Thus, termination ofauxiliary or accessory systems associated with such systems must bebased on battery voltage, timed operation, opening of the cab door orsome combination thereof or another criteria rather than termination ofthe fuel fired HVAC system operation, which may normally be cycling onor off based on a vehicle interior temperature sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the circuit of an independent accessory poweringsystem having no termination means.

FIG. 2 illustrates the same independent circuit with the addition ofautomatic termination means that are independent or are part of any typeof no idle HVAC system.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Although the present invention is described as illustrated in theattached drawings of two possible embodiments, it is to be understoodthat the illustrated embodiments are merely exemplary of the invention,which may be embodied in various forms. Therefore, specific detailsdisclosed herein are not to be interpreted as limiting, but as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention in virtually any appropriate manner.

The left portion of FIG. 1 illustrates the basic power supply circuit ofa typical vehicle accessory. A load at conductor 2 receives power asfollows. When the ignition is on, battery plus [+] is supplied fromconductor 1 via conductors 1, 3 and 4 to load on conductor 2 whenaccessory switch 5 is engaged. When ignition is turned off, power isremoved at conductor 1; and though switch 5 is still engaged or on, theaccessory at conductor 2 is now unpowered. Thus, it can be seen thatmost vehicle accessories are purposely wired to be unpowered when theignition [engine] is off. The need for this is obvious; an accessorythat was accidentally left on [switch 5 engaged] would remain poweredwith the ignition [engine] off and quickly exhaust the vehicle battery.

The balance of FIG. 1 illustrates the addition of an independent,auxiliary but parallel power supply system that can power a vehicleaccessory with the ignition [engine] off. This auxiliary power supplycontrol system is inserted into the existing accessory power supply bysplicing it into the circuit in series as follows. Conductors 1, 3 and 4are parted at 6. Conductor 1 is connected to normally open [NO] contact8 of auxiliary power supply relay 9 via conductor 7. On the other sideof the cut, conductor 4 is connected to conductor 10, which is connectedto transfer contact 11 of relay 9. Relay 9 is grounded at 12 andreceives battery plus [+] power via conductor 13 when the ignition is onand is unpowered when the ignition is off.

With the auxiliary power supply inserted into the vehicle accessorycircuit, the accessory is powered thusly from its normal source when theignition is on. Relay 9 is powered via conductor 13 connected to anignition on battery plus source. With relay 9 powered, transfer contact11 is engaged with contact 8, reconnecting accessory load at conductor 2to its original power source at conductor 1 as follows. Power fromsupply at conductor 1 is transferred via conductor 7, contact 8 of relay9 (now in engagement with transfer contact 11), to conductors 10 and 4,and closed switch 5 to load [accessory] at conductor 2, thus poweringthe accessory from its original source. When the ignition is turned off,relay 9 becomes unpowered because of loss of battery plus [+] onconductor 13, causing transfer contact 11 of relay 9 to disengage fromfixed contact 8 and engage back contact 14. As can be seen, power to theaccessory load at conductor 2 is now removed by both the loss of powerat conductor 1 because the ignition was turned off and because of theopening of the relay contacts 8 and 11.

However, with the dormancy of relay 9, transfer contact 11 is nowengaged with relay back contact 14, providing the opportunity forpowering the accessory load at conductor 2 from a second source with theignition off, as follows. Contact 14 is connected in series to conductor15, switch 16, conductor 17 and fuse 18, to a constant on battery plus[+] source 19. When the optional auxiliary power supply switch 16 isclosed, power is supplied to the vehicle accessory load at conductor 2with the ignition off as follows; constant on battery 19 to fuse 18,conductor 17, closed switch 16, dormant relay back contact 14 (now inengagement with transfer contact 11), conductors 10 and 4, and closedswitch 5 to accessory load at conductor 2, powering the accessory withthe ignition off.

As can be seen, the accessory load at conductor 2 is now powered withthe ignition off and will be so powered until it is disconnectedmanually by turning off either accessory switch 5 or auxiliary powersupply switch 16. Failing to do either with the ignition off could causethe vehicle battery to become discharged. The addition of an automatictermination device would greatly diminish this likelihood.

The addition of such a termination device to the circuit of FIG. 1 isshown in FIG. 2 and may be part of a stand-alone auxiliary accessorypower supply system or as part of a no idle heating, ventilating, andair conditioning [HVAC] system, whether of the fuel burning type, energyrecovery type, battery operated, compressor driven refrigeration typeair conditioner or any other engine off system.

The components of FIG. 2 marked from 1 through 15 are identical infunction to similarly numbered components of FIG. 1 as described above.Added are sensor 30 and relay 25 under its control, and associatedconductors, switches and fuses, functions of which are later describedherein.

Sensor 30 and relay 25 under its control, represent a termination deviceor sensor that is free standing or part of a no idle HVAC systemrepresented by 21. As part of a free standing, ignition off auxiliaryaccessory power supply, its sole function is to terminate operation ofthe auxiliary accessory power supply. As part of any type of no idleHVAC system, its primary function is to terminate operation of the HVACsystem, which then also terminates operation of the auxiliary powersupply.

It is to be understood then, that sensor 30 and relay 25 under itscontrol, represent any sensor system or systems that may individually orin series, freestanding or as part of a no idle system, sense conditionsthat require termination of function of the no idle system or theauxiliary accessory power system or both.

Sensor 30 can then be a battery voltage or battery charge sensor, atiming device, a temperature sensor or any other sensor individually orin series combinations which terminates operation of a no idle system, afreestanding auxiliary accessory power supply system or the combinationof the two (e.g., system 21).

The added components of FIG. 2 function as follows. As previouslystated, with the ignition on and engine running, relay 9 is energized byway of conductor 13 connected to an ignition on battery source. Thisreconnects the accessory load at conductor 2 to its original powersource at conductor 1 by the engagement of relay transfer contact 11with contact 8. When the ignition is turned off, relay 9 becomes dormantand contact 11 disengages from contact 8 and transfers to engagementwith contact 14. The load at conductor 2 receives power with theignition off via contact 11 (now in engagement with contact 14) asfollows.

Contact 14 is connected by way of conductor 15 to the auxiliaryaccessory power supply termination system 21 which is, as previouslymentioned above, an independent system or is part of the terminationcircuit of a no idle HVAC system. Switch 20 connects system 21 toconstant on battery supply 23 via fuse 22. When switch 20 is closed,criteria appropriate to the nature of sensor 30 is evaluated by thesensor 30 and in turn either energizes associated relay 25 or leaves itdormant. For example, if sensor 30 is a battery voltage sensor andsenses adequate voltage, relay 25 will be energized. Or, if sensor 30 isa timer, it will begin its timing cycle and energize relay 25. If sensor30 is an engine coolant temperature sensor, as in energy recovery HVACno idle systems, it also will power relay 25 upon sensing coolanttemperatures to be adequate for system operation. For simplified futurereference herein, this state for sensor 30 is referred to as the sensoractivated state.

With sensor 30 in the activated state, the circuit operates as follows.Relay 25 (grounded at 28), receives power via conductor 29 fromactivated sensor 30, causing its transfer contact 24 to engage contact26. Contact 26 is connected to battery 23 via conductor 27, switch 20,and fuse 22. When the vehicle engine is off, relay 9 is dormant andtransfer contact 11 is engaged with back contact 14, receiving batteryplus from battery 23 as previously described above and thus powering theaccessory load at conductor 2, via closed accessory switch 5 andconductor 10.

As can be seen, power to the accessory load at conductor 2 can beinterrupted by the occurrence of any one of the following four events:opening of the accessory switch 5; starting the engine, which powersrelay 9, disengaging its contact 11 from contact 14; opening of theauxiliary accessory power supply switch 20 [or HVAC system switch 20] orby a termination signal from sensor 30 causing its associated relay 25to disengage contacts 24 and 26.

It is to be understood then that a system to power accessories with theengine [ignition] off, can be a system that is an independent system,that may or may not be equipped with its own termination means or can beconnected or made in such a manner as to be an integral part of any typeof no idle HVAC system sharing the HVAC system's termination means.

It is to be assumed that the electro mechanical system described hereincan functionally be produced by an electronic system, or combinationelectronic electromechanical or computerized vehicle electrical systemas in multiplexed vehicles, and will be recognized by those skilled inthe art as an equivalent to one or more elements of the followingclaims, and shall be covered by such claims to the fullest extentpermitted by law.

It will be understood that the embodiments of the present inventionwhich have been described are illustrative of some of the applicationsof the principles of the present invention. Numerous modifications maybe made by those skilled in the art without departing from the truespirit and scope of the invention, including those combinations offeatures that are individually disclosed or claimed herein. For thesereasons, the scope of the invention is not limited to the abovedescription but is as set forth in the following claims.

1. An electrical system for powering an accessory of a vehicle,comprising: a constant on battery source; an ignition on battery sourcethat is available only when the vehicle ignition is on; a transferswitch electrically connected to the vehicle accessory; an auxiliarypower circuit having an input and an output connected to one another,the input also being connected to the constant on battery source and theoutput being connected to the transfer switch, the auxiliary powercircuit having a termination switch intermediate the input and outputfor interrupting the circuit therebetween and a sensor assemblyconnected to the input and controlling the termination switch; thetransfer switch being alternately connectable to one of the ignition onbattery source and the output of the auxiliary power circuit.
 2. Theelectrical system of claim 1 wherein the termination switch is a relay.3. The electrical system of claim 1 wherein the sensor assembly measuresone of the voltage and battery charge of the constant on battery source.4. The electrical system of claim 1 wherein the sensor assembly measuresthe time that has elapsed since deactivation of the ignition on batterysource.
 5. The electrical system of claim 1 wherein the sensor assemblymeasures the temperature of the coolant in the engine of the vehicle. 6.The electrical system of claim 1 wherein the vehicle accessory is a HVACsystem.
 7. The electrical system of claim 1 wherein the transfer switchcomprises the contacts of a relay.
 8. A method for powering a vehicleaccessory in a vehicle having a battery, an ignition switch, a constanton battery source and an ignition on battery source, the methodcomprising the steps of: connecting the vehicle accessory a transferswitch; connecting the transfer switch to the ignition on battery sourcewhen the ignition switch is on and disconnecting the transfer switchfrom the constant on battery source when the ignition switch is on;connecting the transfer switch to the constant on battery source whenthe ignition switch is off and disconnecting the transfer switch fromthe ignition on battery source when the ignition switch is off;measuring a condition via a sensor; and disconnecting the constant onbattery source from the transfer switch based on the condition measuredby the sensor.
 9. The method of claim 8 wherein the sensor controls arelay and the relay performs the step of disconnecting the constant onbattery source from the transfer switch.
 10. The method of claim 8wherein the condition measured by the sensor is the voltage of theconstant on battery source.
 11. The method of claim 8 wherein thecondition measured by the sensor is the constant on battery source'sremaining charge.
 12. The method of claim 8 wherein the conditionmeasured by the sensor is the time that has passed since the ignitionswitch was disconnected.
 13. The method of claim 8 wherein the conditionmeasured by the sensor is the temperature of engine coolant of thevehicle.
 14. The method of claim 8 wherein the vehicle accessory is aHVAC system.
 15. An electrical circuit for powering an accessory of avehicle, comprising: a first power source; an ignition switch coupled tothe first power source; a second power source; a first relay coupled tothe first and second power sources; a vehicle accessory coupled to thefirst relay, whereby the vehicle accessory is powered by the first powersource when the ignition switch is closed and is powered by the secondpower source when the ignition switch is opened.
 16. The circuit ofclaim 15 wherein the first relay is opened when the ignition switch isturned off.
 17. The circuit of claim 15 wherein the first power sourceis a vehicle based power source.
 18. The circuit of claim 15 wherein thevehicle accessory is a HVAC system.
 19. The circuit of claim 15 furthercomprising a second switch and a fuse, the second switch and the fusebeing electrically coupled between the second power source and thevehicle accessory.
 20. The circuit of claim 15 further comprising asensor and second relay controlled by the sensor, the second electricrelay and sensor electrically coupled between the second power sourceand the vehicle accessory, whereby the sensor actuates the second relaybased on a condition, thereby coupling or decoupling the second powersource from the vehicle accessory and either establishing orinterrupting, respectively, the flow of power from the second powersource to the vehicle accessory.